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目的设计绿色环保的液晶显示器缓冲衬垫,并对其受跌落冲击时的缓冲效果进行有限元分析。方法采用瓦楞纸板折叠成形的方式对液晶显示器的缓冲衬垫进行绿色设计。在ABAQUS有限元软件中建立液晶显示器和缓冲衬垫的实体模型,通过有限元软件模拟液晶显示器运输过程中角跌落的冲击响应,分析缓冲衬垫的缓冲效果。结果角跌落冲击过程中,等效应力云图表明衬垫跌落角处变形较大,应力集中,显示器跌落角处最大应力达到1.293 MPa,但未超过材料的屈服极限。冲击加速度计算结果表明,以1 m的高度跌落时,显示器上易损件的最大冲击加速度为748 m/s2,未超过液晶显示器的许用脆值。结论瓦楞纸板折叠成形的环保缓冲衬垫满足缓冲包装要求,能有效保护显示器抵抗跌落冲击。 相似文献
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The paper presents a modified method for the non‐linear dynamic stress‐strain curve determination with the use of cushion curves provided by the manufacturers of closed‐cell foams. This method consists of two main stages: stage 1 – the cushion curves transformation to the coordinate system of dynamic stress‐energy density, combined with the cubic b‐spline curve approximation, and stage 2 – development of the dynamic stress‐strain curve considering that the area under the curve is equal to the energy density of a collision. The stress‐strain curves are one of the basic parameters of the foam material models used to describe the collision process, in the modelling environments of finite element method (FEM), e.g. LS‐DYNA. Performed verification consisting in the reconstruction of cushion curves using LS‐DYNA showed that the proposed method of the dynamic stress‐strain curves determination is efficient and effective. Taking into account that access to the stress‐strain curves is hindered (cushioning material manufacturers do not publish them), and the access to charts of cushion curves is easier, the proposed method for determining the stress‐strain curves can relevantly shorten the process of preparing the input data, which are required during modelling of spatial structures using FEM. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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目的 分析苹果在运输包装环境中的抗冲击性能,并优化苹果–EPS泡沫缓冲包装设计。方法 以80 mm果径洛川富士苹果为研究对象,通过万能压缩试验机对苹果进行压缩试验,得到应力–应变曲线。通过ABAQUS/Explicit建立苹果运输包装系统有限元模型,并进行有限元仿真分析,其中发泡聚苯乙烯有限元模型采用Crushable Foam模型,苹果采用线弹性力学模型。模拟苹果在沿轴竖直摆放和沿轴水平摆放2种摆放方式下跌落时的冲击响应,并分析不同厚度、密度为28kg/m3的EPS泡沫的缓冲效果。结果 得出苹果的弹性模量为2.44 MPa、屈服极限为0.38 MPa。通过模拟仿真分析可得出,EPS泡沫能有效减缓运输过程中冲击对苹果的损伤,并以此为基础得到了针对该包装系统的缓冲设计。结论 通过与龙格–库塔数值分析法的对比可以得出,本研究以试验为基础,结合仿真分析能为相关果蔬运输提供数据支持和参考。 相似文献
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目的 曲面电视机因其独特的屏幕弯曲设计,在运输与装卸过程中更易受到冲击而破裂,进而失去其使用价值.为降低包装设计成本,提升保护性能,通过仿真技术设计并验证一种曲面电视机缓冲包装系统.方法 基于缓冲包装理论及实际应用对一款曲面电视机进行缓冲包装设计,使用三维建模软件Solidworks绘制包装件模型,运用有限元分析软件ANSYS Workbench中的显示动力学分析模块,对包装件进行全面的跌落仿真分析(2个面跌落、2个棱跌落和1个角跌落)以及倾倒仿真分析.结果 6个工况条件下,屏幕的最大加速度和各零部件应力、应变均在许用范围之内,电视机未发生破损.结论 通过仿真分析验证,所设计的缓冲衬垫在保护曲面电视机方面发挥了显著的防护效果.然而,考虑到成本效益和安全性的平衡,包装结构仍需进一步地优化与改进. 相似文献
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Polymer foams are commonly used in the protective packaging of fragile products. Cushion curves are commonly used within the packaging industry to characterize a foam's impact performance. These curves are two-dimensional representations of the deceleration of an impacting mass versus static stress. Cushion curves are currently generated from exhaustive experimental test data. This study represents the first time that the physics of the mass-cushion impact have been analysed by modelling the foam as nonlinear, continuous rod. Using a single mode of vibration and excluding the effects of damping, the maximum displacement during the impact can be obtained from a polynomial describing the maximum elastic energy in the foam. The displacements can be used to recover the amplitude of the deceleration shock pulse. Numerical and analytical analysis of the model with damping is considered in its ability to predict the shock pulse shape, duration, and amplitude at various static stresses, foam thickness, and drop heights as compared with experimental data. Furthermore, both the analytical and numerical results agree and are primarily within the expected lab-to-lab variability of 18% documented in ASTM D1596 - Standard Test Method for Dynamic Shock Cushioning Characteristics of Packaging Material. 相似文献
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A comparison of static and dynamic cushioning properties of polyethylene foam is discussed in this paper. A dynamic factor function is defined and obtained from the analysis on the experimental data from compression and cushion tests. The deformation energy per unit volume is taken into consideration to make an estimate of the maximum strain and dynamic stress data in an impact, and the peak acceleration can be predicted from the compression data corrected for the dynamic effects by the dynamic factor function. Then, the cushion curves at almost every test condition, such as different drop heights or thickness of cushioning material, can be approximated by a specially developed computer code using Matlab. This research can assist in determining the accuracy of cushion curves for all variants of a particular cushioning material from the dynamic factor function and compression test data. This new procedure will greatly simplify the experimental process for determining cushion curves. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Cushion curves enable packaging designers to optimize a design solution for a given product fragility and expected distribution environment drop height. The industry accepted techniques for developing these curves are time intensive and devoid of a physical understanding of the materials and the physics involve in energy absorption. This paper delves into a qualitative understanding of the dynamics of a platen impacting an open cell foam cushion material. An hyperelastic material model is used to describe the foam's nonlinear stress–strain relationship, while its damping and hysteretic behaviour are represented with linear viscoelasticity. Using a simple nonlinear, discontinuous model of a drop test along with numerical simulations, the study examines the physics of the impact. The numerical studies show that the model is able to provide predictions of the shock pulse's shape, duration and amplitude at various static stresses and drop heights. The dynamic cushion curves generated by the model retain the characteristic concave upward ‘trough’ shape of the experimental curves. Furthermore, the model shows that the optimal amplitude of shock absorbed for a given set of drop conditions depends on the foam's thickness and cross‐sectional area. Lastly, the model is validated using the comparison of a predicted curve and experimental data captured using a cushion tester. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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目的为了满足价值工程节约成本的要求,对某出口海外的木包装容器结构进行优化设计。方法首先对产品功能进行分析,设计新包装的结构方案,由原有的卧式包装优化为用材更少的立式包装,然后运用理论力学知识对泵体进行稳定性计算和底座强度分析,然后运用CATIA建立三维模型,运用有限元分析软件Ansys Workbench对模型进行强度校核,最后根据国际安全运输协会包装测试标准对样品进行振动、冲击、跌落测试。结果新包装通过了振动冲击跌落测试,优化后的木包装容器满足抗冲击的强度要求,满足不会发生倾覆的功能要求,木材用料节约了40%,铁支架材料节约了100%,每年全球公司节约成本约360万元。结论新包装在满足产品功能的基础上,大大节约了成本,满足了价值工程以最少的费用换取所需要的功能的要求;同时也为跨国包装设计工程师提供一种包装解决方案和技术参考。 相似文献
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Fracture and tensile tests were conducted on a composite biomaterial consisting of polycarbonate matrix and calcium phosphate fibers. The fibers were short and randomly oriented. Test results were compared for composites with and without a surface treatment of the fibers.
A nonlinear finite element method was used to predict the maximum loads on pre-cracked panels. The method used the unnotched stress–strain behavior to predict the failure process in notched panels. A cohesive stress zone near the crack tip was used to model damage, stable crack growth, and failure. As in the experiments, the predicted loads were lower for the composite with coated fibers. For both materials, the predicted maximum loads were within the 6% of the experimental loads. 相似文献
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用有限元法计算飞秒激光双光子成型点弹性模量 总被引:1,自引:0,他引:1
采用有限元法对材料为SCR500的飞秒激光双光子成型点力学性能进行建模及仿真计算,得出了不同弹性模量下成型点与探针之间的作用力.进而利用原子力显微镜接触模式,选用无针尖探针,测量了成型点的力学性能,得出了相同位移载荷下成型点与探针之间的作用力.将测量结果和仿真结果进行比较,推算出成型点的弹性模量.分析结果表明。双光子固化成型点的弹性模量大约为宏观材料弹性模量的1/7.这为进一步研究双光子飞秒激光加工微器件的力学性能提供了基础. 相似文献
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《Advanced Composite Materials》2012,21(4):343-358
Titanium matrix composites (TMCs) is considered as a candidate material for landing gear structures of the aircraft, which requires the damage tolerant consideration. In order to investigate the damage behavior of SiC-fiber/titanium matrix composites subjected to foreign object impact, low-velocity impact experiments are conducted. Finite element modeling to simulate the damage behavior of TMCs is developed considering the plastic deformation and the damages. Numerical results of mechanical response and damage behavior are compared with experimental results. It is shown that the developed modeling can capture the impact damage of TMCs. In the last part of the present study, a prototype of TMC landing gear structure is fabricated. Impact damage behavior and residual compressive strength are evaluated, and the results are compared with numerical simulation. 相似文献
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利用有限元分析软件ANSYS,通过变化栅宽、沟宽及栅极位置等因素,模拟了共面栅探测器在不同的电极设计时的电势分布,并讨论了电极分布不对称时所产生的边缘对感应信号的影响,显示了具有优化设计的共面栅电极,可以进一步提高探测器的能量分辩率。 相似文献
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目的研究鸡蛋缓冲包装的结构及缓冲效果。方法利用Ansys/LS-DYNA有限元分析软件,对所设计的缓冲包装结构在0.6 m的跌落高度进行角跌落仿真,得到鸡蛋和包装件在与地面接触瞬间、回弹瞬间及跌落结束瞬间的等效应力云图及危险点的加速度曲线,模拟鸡蛋在流通过程中包装件受到冲击和振动时鸡蛋的应力变化,以检验缓冲包装的缓冲效果。结果在跌落过程中,包装件与地面接触瞬间的等效应力最大,为0.784 MPa,小于瓦楞纸板的极限应力;危险点的最大加速度为59g,小于鸡蛋的脆值60g。结论设计的缓冲包装能够起到很好的缓冲效果,可有效提高鸡蛋运输过程中的安全性。 相似文献
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目的研究冰箱在运输过程中的振动和冲击特性。方法利用Pro/E建立冰箱缓冲包装模型,并对模型进行适当简化,然后利用有限元分析软件Ansys对冰箱缓冲包装的振动和冲击特性进行模拟分析计算。结果求出了冰箱缓冲包装的固有频率与固有振型,以及在公路运输过程中受到振动和冲击下的动态响应。结论所提出的模拟产品包装系统的振动和冲击特性的方法,不仅缩短了产品的设计周期,而且为电子产品的包装设计提供了依据。 相似文献
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为了预测跌落碰撞下球栅阵列(BGA)封装中无铅焊点的失效,采用ABAQUS软件来模拟跌落碰撞过程中焊点的应力分布.首先建立圆形电路板(PCB)组件的有限元模型,接着用模态试验和有限元模拟相结合的方法确定有限元模型的边界条件和PCB的阻尼参数,然后运用ABAQUS有限元软件模拟PCB组件从三种高度下跌落碰撞过程中BGA封装中无铅焊点的拉应力分布.结果表明:封装最外圈四个拐角焊点的拉应力最大,最大拉应力出现在焊点靠近封装的一侧.由此预测最外圈拐角的焊点最易失效,焊点失效的位置在靠近封装一侧. 相似文献
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目的研究某工控设备缓冲包装的跌落数值仿真技术。方法建立一种工控设备缓冲包装的跌落仿真模型,从仿真结果中获得跌落加速度曲线和产品的等效应力云图,观察缓冲包装的变形动画;对比缓冲包装的跌落试验,验证了跌落仿真模型;基于验证的跌落仿真模型,研究EPE衬垫尺寸对缓冲包装跌落冲击响应的影响规律。结果跌落仿真与跌落试验的加速度曲线趋势基本吻合,峰值加速度相差仅0.8%;仿真的等效应力云图显示产品满足强度要求,未发生永久变形,与跌落试验结果一致。对EPE衬垫尺寸的跌落缓冲研究表明,相对于缓冲面积,缓冲厚度的大小对跌落加速度具有更为显著的影响。结论建立的跌落仿真模型具有较高的模拟精度,为产品的缓冲包装结构设计及其优化奠定了良好基础。 相似文献